Abstract: A color transformation matrix K transforms device dependent color imaging signals RGB into device independent color imaging signals XYZ. The transformation matrix K includes a set of coefficients kn. An optimization value is calculated for the transformation matrix as a function of the coefficients within the transformation matrix having a value less than zero. The values of the coefficients within the transformation matrix are then adjusted; and a minimal optimization value is determined for the transformation matrix, which preferably has coefficients with values that are greater than zero. The optimization procedure seeks to minimize the optimization value by adjusting the values of the coefficients within the transformation matrix, such that the coefficients within the matrix are all positive values. This added constraint on the transformation matrix in the minimization technique will lead to larger residual color errors.